OnSpam

Author: Célestin Matte, while working for SPI

The instance I’m managing has a policy of allowing anyone to create tickets. As a result, it is occasionally struck with email loops, when poorly-configured systems auto-respond to the ticket creation confirmation email.

In order to stop these email loops, I created this scrip that blocks users that create more than a certain number of tickets in a day.

This will add a comment in the last ticket indicating the block. Blocked users will be informed through “permission denied” emails.

Note: Technically, this will not stop the email loop between RT and users (you can’t prevent emails from being sent from scrips), but it will stop new tickets creation. I use this method because I’m not hosting this instance and have therefore no access to server-side settings, which would be necessary to completely break the loop.

This can also be used to block spammers.

Scrip

• Description: Ticket creation rate limiting
• Condition: On Create
• Action: User Defined
• Template: Blank

Custom action preparation code:

my $user = $self->TransactionObj->Creator;
my $limit = 30; # Maximum tickets per day

# A user that won't be affected by the rate limitation
my $excluded_user = 'someuse@domain.com';

if ($self->TicketObj->RequestorAddresses eq $excluded_user) {
    return 0; # Allow the ticket creation without limits for excluded user
}

# Get today's date in a format RT can use
my $today = RT::Date->new($RT::SystemUser);
$today->Set(Format => 'unknown', Value => 'today');
$today->SetToMidnight();

# Search for tickets created by the user today
my $tickets_today = RT::Tickets->new($RT::SystemUser);
$tickets_today->LimitCreated(OPERATOR => '>=', VALUE => $today->ISO);
$tickets_today->Limit(FIELD => 'Creator', VALUE => $user);

if ($tickets_today->Count > $limit) {
    $self->TicketObj->Comment(Content => "Rate limit reached for user" );
    return 1; # Prevent ticket creation
}

return 0; # Allow ticket creation to proceed

Custom action commit code:

# Delete the ticket
# my $ticket = $self->TicketObj;
#$ticket->Delete();

my $user = $self->TicketObj->CreatorObj;

my $res = $user->SetEmailAddress("");
my $res2 = $user->SetDisabled(1);

$self->TicketObj->Comment(Content => "Email address change result: $res\nUser disabling result: $res2");

return 1;